The present invention relates generally to a method, system, and computer program for multi-tier data storage. More particularly, the present invention relates to a method, system, and computer program for hybrid cloud storage.
Data in the enterprise is growing at an alarming rate led by growth in unstructured data. Thus, enterprises need a multi-site data replication solution that provides a Network Access Server (NAS) interface, as a high performance tier, backed with a cheaper, highly scalable cloud tier. Hybrid cloud storage places inactive data to cloud object storage. This frees up high performance storage capacity which can be used for more active data, thus reducing storage costs. Inactive data constitutes a large proportion of data in the enterprise. Migrating cooler/cold data to lower cost cloud storage tier could result in cost savings.
One such hybrid cloud storage program is IBM® Transparent Cloud Tiering (TCT), which bridges an on-premises high performance NAS tier such as IBM Spectrum Scale and cheaper, scalable multi-site cloud object store tier such as IBM® Cloud Object Store (Cleversafe®). (IBM and CLEVERSAFE are registered trademarks of IBM, Corp.). However, current object storage gateways treat object storage and file storage tiers completely separately. Thus, in multi-site storage systems, data is replicated across the multiple storage sites at the hot data storage tier and then again at the cold data storage tier. This results in data being generally distributed across a Wide Area Network (WAN) by the hot data storage tier, and then over the WAN again when the data cools by the cold storage tier. Therefore, the current state of technology has data that is replicated across sites over a WAN multiple times. This procedure is an inefficient use of resources as data has already been replicated at the file storage tier and thus does not need to be transferred again at the cold storage tier. Further, a WAN is an expensive resource and thus it is optimal to limit usage of a WAN when possible. Thus, a more efficient and cost effective solution for hybrid cloud storage is needed.